I. ˈtə-n ə l noun
Etymology: Middle English tonel cask, tun, from Anglo-French, from tone tun
Date: 1508
1. : a hollow conduit or recess : tube , well
2.
a. : a covered passageway ; specifically : a horizontal passageway through or under an obstruction
b. : a subterranean gallery (as in a mine)
c. : burrow
• tun·nel·like -n ə l-ˌ(l)īk adjective
II. verb
( -neled or -nelled ; -nel·ing or tun·nel·ling ˈtən-liŋ, ˈtə-n ə l-iŋ)
Date: 1795
intransitive verb
1. : to make or use a tunnel
2. physics : to pass through a potential barrier
electrons tunnel ing through an insulator between semiconductors
transitive verb
: to make a tunnel or similar opening through or under ; also : to make (one's way) by or as if by making a tunnel
• tun·nel·er ˈtən-lər, ˈtə-n ə l-ər noun